When a new version of Nextcloud becomes available, all clients give a notification “Update to Nextcloud n.n.n is available”.
I have my doubts if it is useful that clients show this message. End-users that just make use of the cloud services in general have no interest in server versions. But, most important, they cannot do anything with this information. Only the system administrator can perform an upgrade.
So I suggest to remove the message from the clients, or make it configurable and disabled by default. System admins can then enable it in their own clients if they want.